12. For the function f(x) = 3x4 + M3 + bx? + ex + d, a. nd constants a, b, c, and d that guarantee that the graph of f will have horizontal tangents at (2, 73) and (0, 9). b. there is a third point that has a horizontal tangent. Find this point. c. For all three points, determine whether each corresponds to a relative max- imum, a relative minimum, or neither